• Molecular & Cellular Toxicology
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• v.1 no.4
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• pp.256-261
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• 2005

The recent DNA microarray technology enables us to understand gene expression profiling in cell line and animal models. The technology has potential possibility to comprehend mechanism of multiple genes were related to compounds which have toxicity in biological system. So, microarray system has been used for the prediction of toxicity through gene expression induced by toxicants. It has been shown that compounds with similar toxic mechanisms produce similar changes in gene expression in vivo system. Here we focus on the use of toxicogenomics for the determination of gene expression analysis associated with hepatotoxicity in rat liver and cell line (WB-F344). Methotrexate (MTX) is a chemotherapy agent that has been used for many years in the treatment of cancer because it affects cells that are rapidly dividing. Also it has been known the toxicity of MTX, in a MTX abortion, it stops embryonic cells from dividing and multiplying and is a non-surgical method of ending pregnancy in its early stages. We have shown DNA microarray analyses to assess MTX-specific expression profiles in vivo and in vitro. Male Sprague-Dawely VAF+ albino rats of 5-6 weeks old and WB-F344 cell line have been treated with MTX. Total RNA was isolated from Rat liver and cell line that has treated with MTX. 4.8 K cDNA microarray in house has been used for gene expression profiling of MTX treatment. We have found quite distinct gene expression patterns induced by MTX in a cell line and in vivo system.

• Molecular & Cellular Toxicology
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• v.3 no.2
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• pp.107-112
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• 2007

o-Nitrotoluene is used to synthesize artificial dyes and raw materials of urethane resin. In this study, we have carried out in vitro genetic toxicity tests and microarray analysis to understand the underlying mechanisms and the mode of action of toxicity of onitrotoluene. TA1535 and TA98 cells were treated with o-nitrotoluene to test its toxicity by basic genetic toxicity test. Ames and two new in vitro micronucleus and COMET assays were applied using CHO cells and L5178Y cells, respectively. In addition, microarray analysis of differentially expressed genes in L5178Y cells in response to o-nitrotoluene was analyzed using Affymatrix genechip. The result of Ames test was that o-nitrotoluene treatment did not increase the mutations both in base substitution strain TA1535 and in frame shift TA98. o-Nitrotoluene has not increased micronuclei in CHO cells. But onitrotoluene increased DNA damage in L5178Y cell. Two-hundred two genes were initially selected as differentially expressed genes in response to o-nitrotoluene by microarray analysis and forty four genes among them were over 2 times of log fold changed. These forty four genes could be candidate biomarkers of genetic toxic action of o-nitrotoluene related to induction of mutation and/or induction of micronuclei and DNA damage. Further confirmation of these candidate markers related to the DNA damage will be useful to understand the detailed mechanism of action of o-nitrotoluene.

• Journal of Food Hygiene and Safety
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• v.22 no.1
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• pp.1-14
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• 2007

The term, "food safety", has traditionally been viewed as a practical science aimed at assuring the prevention acute illnesses caused by biological microorganisms, and only to a minor extent, chronic diseases cause by chronic low level exposures to natural and synthetic chemicals or pollutants. "food safety" meant to prevent microbiological agents/toxins in/on foods, due to contamination any where from "farm to Fork", from causing acute health effects, especially to the young, immune-compromised, genetically-predisposed and elderly. However, today a broader view must also include the fact that diet, perse (nutrients, vitamins/minerals, calories), as well as low level toxins and pollutant or supplemented synthetic chemicals, can alter gene expressions of stem/progenitor/terminally-differentiated cells, leading to chronic inflammation and other mal-functions that could lead to diseases such as cancer, diabetes, atherogenesis and possibly reproductive and neurological disorders. Understanding of the mechanisms by which natural or synthetic chemical toxins/toxicants, in/on food, interact with the pathogenesis of acute and chronic diseases, should lead to a "systems" approach to "food safety". Clearly, the interactions of diet/food with the genetic background, gender, and developmental state of the individual, together with (a) interactions of other endogenous/exogenous chemicals/drugs; (b) the specific biology of the cells being affected; (c) the mechanisms by which the presence or absence of toxins/toxicants and nutrients work to cause toxicities; and (d) how those mechanisms affect the pathogenesis of acute and/or chronic diseases, must be integrated into a "system" approach. Mechanisms of how toxins/toxicants cause cellular toxicities, such as mutagenesis; cytotoxicity and altered gene expression, must take into account (a) irreversible or reversal changes caused by these toxins or toxicants; (b)concepts of thresholds or no-thresholds of action; and (c) concepts of differential effects on stem cells, progenitor cells and terminally differentiated cells in different organs. This brief Commentary tries to illustrate this complex interaction between what is on/in foods with one disease, namely cancer. Since the understanding of cancer, while still incomplete, can shed light on the multiple ways that toxins/toxicants, as well as dietary modulation of nutrients/vitamins/metals/ calories, can either enhance or reduce the risk to cancer. In particular, diets that alter the embryo-fetal micro-environment might dramatically alter disease formation later in life. In effect "food safety" can not be assessed without understanding how food could be 'toxic', or how that mechanism of toxicity interacts with the pathogenesis of any disease.

• The Korean Journal of Pharmacology
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• v.32 no.2
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• pp.201-209
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• 1996

Restoration of the blood flow after a period of ischemia is accompanied by generation of toxic oxygen radicals. This phenomenon may account for the occurrence of reperfusion-mediated tissue injury in ischemic hearts. In in vitro studies, although oxygen radicals can be generated from a variety of sources, including xanthine oxidase system, activated leucocytes, mitochondria and others, the most important source and mechanism of oxygen radical production in the post-ischemic reperfused hearts is unclear. In the present study, we tested the hypothesis that the respiratory chain of mitochondria might be an important source of oxygen radicals which are responsible for the development of the reperfusion injury of ischemic hearts. Langendorff-perfused, isolated rat hearts were subjected to 30 min of global ischemia at $37^{\circ}C$, followed by reperfusion. Amytal, a reversible inhibitor of mitochondrial respiration, was employed to assess the mitochondrial contributions to the development of the reperfusion injury. Intact mitochonria were isolated from the control and the post-ischemic reperfused hearts. Mitochondrial oxygen radical generation was measured by chemiluminescence method and the oxidative tissue damage was estimated by measuring a lipid peroxidation product, malondialdehyde(MDA). To evaluate the extent of the reperfusion injury, post-ischemic functional recovery and lactate dehydrogenase(LDH) release were assessed and compared in Amytal-treated and -untreated hearts. Upon reperfusion of the ischemic hearts, MDA release into the coronary effluent was markedly increased. MDA content of mitochondria isolated from the post-ischemic reperfused hearts was increased to 152% of preischemic value, whereas minimal change was observed in extramitochondrial fraction. The generation of superoxide anion was increased about twice in mitochondria from the reperfused hearts than in those from the control hearts. Amytal inhibited the mitochondrial superoxide generation significantly and also suppressed MDA production in the reperfused hearts. Additionally, Amytal prevented the contractile dysfunction and the increased release of LDH observed in the reperfused hearts. In conclusion, these results indicate that the respiratory chain of mitochondria may be an important source of oxygen radical formation in post-ischemic reperfused hearts, and that oxygen radicals originating from the mitochondria may contribute to the development of myocardial reperfusion injury.

• Korean Journal of Weed Science
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• v.30 no.2
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• pp.111-121
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• 2010

Differential tolerance to protoporphyrinogen oxidase (Protox)-inhibiting herbicides, oxyfluorfen was observed between leaf ages in squash. Physiological responses to oxyfluorfen, including leaf injury, cellular leakage, accumulation of tetrapyrroles, and antioxidative enzymes activity, were investigated in leaf age classes of squash to identify mechanisms of oxyfluorfen tolerance. Leaf 1, 2, and 3 injuries for Joongangaehobak were >10,000, 1,286, and 1.6-fold higher than that of leaf 4, after treatment of oxyfluorfen. On the other hand, leaf 1, 2, and 3 injuries for Sintowjahobak were 725, 366, and >0.6-fold higher than that of leaf 4, after treatment of oxyfluorfen. However, in contrast to oxyfluorfen treatment results, leaf injury of squash leaf 4 treated with paraquat was much smaller than in leaves 1, 2 and 3. Electrolyte leakage from the tissues treated with oxyfluorfen was higher in the youngest leaf (Leaf 4) than in the older leaves 1, 2, and 3. Differential leaf response to oxyfluorfen of squash appears to be due in large part to differences in protoporphyrin IX (Proto IX), Mg-Proto IX, and Mg-Proto IX monomethyl ester accumulation in treated leaves. In contrast, leaf 4 had higher activities of superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, and glutathione reductase than leaf 1 after treatment with oxyfluorfen. However, the induction in antioxidant activity in leaf 4 was not enough to overcome the toxic effects of a Protox inhibitor, oxyfluorfen, so the leaf eventually died.

• Journal of Applied Biological Chemistry
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• v.61 no.3
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• pp.275-281
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• 2018

Pinus densiflora root (PDR) is used as a medicinal plant. In this study, we investigated whether the PDR extract has anti-inflammatory activities. Cell viability assays showed that the extract was not toxic toward RAW 264.7 cells at concentrations up to $10{\mu}g/mL$. At $10{\mu}g/mL$, the extract decreased nitric oxide (NO) content to 40% of the control level. The protein expression of inducible nitric oxide synthase (iNOS), which generates NO, decreased with increasing concentrations of the extract. Prostaglandin $E_2$ ($PGE_2$) levels were significantly inhibited by over 50% in the presence of $10{\mu}g/mL$ of the extract. The protein expression of cyclooxygenase-2 (COX-2), which generates $PGE_2$, decreased with increasing concentrations of the extract. Proinflammatory cytokines, such as tumor necrosis factor-alpha ($TNF-{\alpha}$), interleukin-6 (IL-6), and $IL-1{\beta}$, were detected in RAW 264.7 cells after lipopolysaccharide (LPS) treatment. The extract did not affect the levels of $TNF-{\alpha}$ and IL-6, but it significantly inhibited the level of $IL-1{\beta}$. It also completely inhibited the transcription of nuclear factor-kappaB ($NF-{\kappa}B$). These results indicate that the PDR extract reduces inflammatory response-related proteins, such as NO, $PGE_2$, iNOS, and COX-2, in LPS-induced RAW 264.7 cells via the regulation of $NF-{\kappa}B$. Consequently, we have provided a mechanism to explain the anti-inflammatory effect of the PDR extract; that is, it exerts such an effect by regulating $NF-{\kappa}B$. The PDR extract can therefore be considered as an effective anti-inflammatory agent.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.5
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• pp.304-311
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• 2012

Chlorinated ethylenes such as perchloroethylene (PCE) and trichloroethylene (TCE) are widely used as industrial solvents and degreasing agents. Because of improper handling, these highly toxic chlorinated ethylenes have been often detected from contaminated soils and groundwater. Biological PCE dechlorination activities were tested in bacterial cultures inoculated with 10 different environmental samples from sediments, sludges, soils, and groundwater. Of these, the sediment using culture (SE 2) was selected and used for establishing an efficient PCE dechlorinating enrichment culture since it showed the highest activity of dechlorination. The cathode chamber of bioelectrochemical system (BES) was inoculated with the enrichment culture and the system with a cathode polarized at -500 mV (Vs Ag/AgCl) was operated under fed-batch mode. PCE was dechlorinated to ethylene via TCE, cis-dichloroethylene, and vinyl chloride. Microbial community analysis with polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) showed that the microbial community in the enrichment culture was significantly changed during the bio-electrochemical PCE dechlorination in the BES. The communities of suspended-growth bacteria and attached-growth bacteria on the cathode surface are also quite different from each other, indicating that there were some differences in their mechanisms receiving electrons from electrode for PCE dechlorination. Further detailed research to investigate electron transfer mechanism would make the bioelctrochemical dechlorination technique greatly useful for bioremediation of soil and groundwater contaminated with chlorinated ethylenes.

• Journal of Korean Medicine Rehabilitation
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• v.21 no.1
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• pp.1-22
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• 2011

Objectives : This study was undertaken to verify the effects of Wolbigachul-tang1(WBCEx1) on obesity using high fat diet-induced male mice and to investigate the molecular mechanisms involved. Methods : 8-week old C57BL/6 mice were divided into 5 groups; lean control, obese control, WBCEx1, 2, 3. After mice were treated with WBCEx1(water extract), 2(30% ethanol extract), 3(water extract; Ephedra sinica Stapf., Gypsum fibrosum) for 12 weeks, body weight gain, feeding efficiency ratio, plasma lipid and glucose metabolism, the messenger RNA(mRNA) expression of peroxisome proliferator activated receptor(PPAR)$\alpha$ target genes were measured. In addition, $PPAR{\alpha}$ target gene expression was examined in liver, white adipose tissue and skeletal muscle. Results : 1. WBCEx1-treated mice had significantly lower body weight gain and feeding efficiency ratio. 2. Consistent with the effects on body weight gain, WBCEx1 decreased the weights of epididymal and retroperitoneal white adipose tissue, inguinal subcutaneous adipose tissue, and brown adipose tissue. 3. WBCEx1 significantly decreased plasma triglyceride and total cholesterol levels. 4. The size of adipocytes were significantly decreased by WBCEx1, whereas the adipocyte number per unit area was increased. Hepatic lipid accumulation was decreased by WBCEx1. 5. WBCEx1 did not affect the mRNA expression of $PPAR{\alpha}$ target genes in liver, adipose tissue, and skeletal muscle. 6. Plasma asparate aminotransferase(AST), alanine aminotransferase(ALT), blood urea nitrogen(BUN) and creatine concentrations were in the physiological range. Liver and kidney weights were significantly lower following WBCEx treatment compared with obese controls, indicating that WBCEx does not show any toxic effects on liver and kidney. Conclusions : These results suggest that WBCEx1-induced body weight reduction is associated with appetite control and mediated by a mechanism other than the activation of $PPAR{\alpha}$.

• Journal of Ginseng Research
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• v.44 no.1
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• pp.105-114
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• 2020

Background: Exploring the pharmacokinetic (PK) changes of various active components of single herbs and their combinations is necessary to elucidate the compatibility mechanism. However, the lack of chemical standards and low concentrations of multiple active ingredients in the biological matrix restrict PK studies. Methods: A putative multiple reaction monitoring strategy based on liquid chromatography coupled with mass spectrometry (LC-MS) was developed to extend the PK scopes of quantification without resorting to the use of chemical standards. First, the compounds studied, including components with available reference standard (ARS) and components lacking reference standard (LRS), were preclassified to several groups according to their chemical structures. Herb decoctions were then subjected to ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry analysis with appropriate collision energy (CE) in MS² mode. Finally, multiple reaction monitoring transitions transformed from MS² of ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry were used for ultrahigh-performance liquid chromatography coupled with triple quadrupole mass spectrometry to obtain the mass responses of LRS components. LRS components quantification was further performed by developing an assistive group-dependent semiquantitative method. Results: The developed method was exemplified by the comparative PK process of single herbs Radix Ginseng (RG), Radix Polygala (RP), and their combinations (RG-RP). Significant changes in PK parameters were observed before and after combination. Conclusion: Results indicated that Traditional Chinese Medicine combinations can produce synergistic effects and diminish possible toxic effects, thereby reflecting the advantages of compatibility. The proposed strategy can solve the quantitative problem of LRS and extend the scopes of PK studies.

• Journal of Korea Soil Environment Society
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• v.3 no.1
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• pp.55-63
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• 1998

This study investigates the contamination mechanism of soil by drainages including acid rains around mining waste sites, and suggests the quantitative methods of prevention against soil contaminations and its alternatives. For these purposes, the dissolution of arsenic in soils, which is one of toxic heavy metals, has been examined experimentally using the artificial acidic solution. Also, in order to prevent dissolution of arsenic by acid rain, the effects of limestone for the neutrality method on the soil were investigated. The arsenic in soil specimen was dissolved by strong acidic solution below pH1.0. The maximum amount of dissolved arsenic increased with decreasing pH value. Furthermore, it was found very effective to use limestones for the neutrality method. The neutralization of limestones in acidic solution was found to follow the equation of chemical reaction-controlling formulation in unreacted-core models.